New classification for the isothiazolinone OIT?

One of the issues discussed when ECHA's Committee for Risk Assessment met at the end of November 2018 was the proposed update to the existing harmonized classification of the isothiazolinone OIT (CAS 26530-20-1), a biocide commonly used within metalworking. The proposal was to, among other things, lower the specific concentration limit (SCL) for when OIT is classified as allergenic from 500 ppm to 50 ppm. However, the Committee for Risk Assessment did not consider that 50 ppm was low enough and recommends that the SCL is set to 15 ppm. That is the same SCL level that has already been given to the isothiazolinones MIT and CMIT/MIT. (Read more about that and about isothiazolinones in general in my previous blog post about MIT).

The Finnish Institute of Occupational Health is one of the parties who gave recommendations to the Committee for Risk Assessment. They refered to several studies External link, opens in new window. that showed evidence of cross-reactivity between the isothiazolinones OIT, MIT and BIT. That means that a person that is already sensitized to MIT could be allergic to OIT without ever having been expopsed to OIT before. The Committee for Risk assessment paid particular attention to this information when giving their recommendation.